Improvement in box for case-harden ing



J. GREENE.

Box for Case Hardenng,

Patented Nov. 3, 1863.

IWW Whff: ywrwo l #MEQ I NrrED STATES 'PATENTg OFFICE.

'JAMES GREENE, or PE'ov'rDEN'cE, RHODE isLAVNn.

iMPnovElvi-'ENUN Box Fon cAsE-HARDENING. i

Specification forming part' of Letters Patent Nad-'05477, datedNo'vembeS, 1863.

To all whom bin/ay concern:

Be it known that I,l JAMES GREENE, of Providence, in the county ofProvidence and.

State of Rhode Island, have invented a new vy y, Fig. 3; Fig. 3 a planor top view of the same with the lid or top removed.

Similar letters of reference indicate corresponding partsin the severalfigures.

The object of this invention is to obtain a box for case-hardening whichwill admit of the articles to be operated upon being heated in a moreuniform manner than hitherto, and after being subjected a requisite timeto the heat in contact with the bone-dust or other material used andthen admit of the articles being' suddenly and properly precipitatedfrom the box into the water or other liquid which tempers them.

The ordinary way of case-hardening consists in placing the articles tobe operated upon in a metal box containing certain animal matters-suchas the hoofs, horns, bones, and skin-in a charred orV coarsely-poundedstate, the articles being surrounded on all sides by a layer fromone-half to one inch thick. The box is then heated a certain length oftime, and the articles are then turned out of the box into the water orother tempering-liquid by inverting the latter.

The difficulties attending this operation are two-fold, 'to-wit: thearticles at the center of the box are not subjected to so great aheat asthose near its sides, for the reason that the exterior of the box isonly in contact with the heat, and in inverting the box in order todischarge its contents the latter descends into the water or othertempering-liquid with a rotary motion, which frequently warps thearticles.

My invention fully obviates these difficulties, and consists, h'rst, inconstructing the box with a central opening or i'lue extending entirelythrough it, and having the bottom of the box provided with supports orlegs, so that it will be elevated a short dist-ance above the bottom ofthe oven or shelf which supports it, and admit of the heat passing upthrough the central flue so as to heat the box at4 its center, therebycausing-the articles rotary motion.

To enable those skilled in the art to fully understandk and construct myinvention, I will proceed to describe it.

A represents a box, which may be constructed of cast or wrought metal,and of rectangular or other proper way. The box is formed with a centralopening ory iiue, a, extendingentirely through it, the lid b having asimilar opening, c, so that when it is adjusted to the box it may fitsnugly around the top of a. The lid b is secured to the box A by boltsd, arranged in any proper way. The ends of the box are provided withlugs or cleats e, the use of which will be presently stated, and thesides of the box are provided with ears f for the convenience ofgrasping it by a proper implement when placed into and removed from theoven. These ears f may be either at the sides or ends of the box, asdesired.

The bottom g of the box is provided with an opening, c', like that otthe lid, and is attached to the latter by hinges or joints h, and thebox at the side opposite to that where the hinges are attached has acatch, B, secured to it. This catch B may be arranged in various ways.The one shown in the drawings, Figs. 2 and 3, consists of two hooks, M,at the ends of a shaft, j, which is fitted in bearings 7c kattached tothe side of the box, and allowed to turn freely therein. This shaft jhas a handle, l, attached to it. 1

The hooks i' t', when the bottom g is closed in contact with the box,catch under the bottom g and hold it snugly to the box, as shown clearlyin Fig. 2; and by turning the shaftj, through the medium of the handleZ, the hooks o' t may be freed from the bottom g, and the latter allowedto drop, as indicated by the red outline in Fig. 2. This bottom may havea weight attached to it, as shown inv red, in order to aid its suddendropping. The bottom g has feet or legs m attached to it, as shown inFigs. 1 and 2.

By this construction it will be seen that e e t M i 40.47%

when the box is placed in the oven, (shown in red outline in Fig. 1,)the heat will be allowed to pass through the central opening or iiue, a,as Well as around thesides and over the top or lid b of the box, and thekcontents of f with a proper tool, and placed over a cask containingtheWater or temperingfluid, the lugs or cleatse e resting-on bars tosupport the box. The catch B is then actuated and the bottom g of thebox thereby released, the bottom instantly dropping and discharging thecontents of thel box into the cask, the articles to be hardened beinglet bodily down without any turning movement, thereby insuring thehardening of the articles Without the same being Warped or twisted-acontingency which is liable to occur when the articles are turned outofthe box by inverting the same.

i By means of the hinged bottom the articles are also very 'suddenlyprecipitated into the tempering-Huid, much more so than when turned outof the box, and 4the articles are consequently not so liable to beoxidized by contact with the air. This is notan unimportant feature ofthe invention.

I Wouldremark that I do not confine my self tothe hinged bottom g, for asliding one might be used, although it would be inf'erior to the hingedone. Still it would be a great improvement over the old box.

Having thus described my invention, what I claim as new, and desiretosecure by Letters Patent, is-l A box for case-hardening, constructedwith a central opening or flue and a movable dischargingbottom, all asherein shown and described, for the purpose set forth.

JAMES GREENE.

Witnesses:

CORNELIUS CLANOY, EUGENE OAHILL.

